The use of laser beams as alignment tools to check the proper relationship of frame parts and body panels in vehicles has become recently known. Such devices as the LAZER ALIGNER (TM) made by the Kansas Jack Division of Hein-Werner Corporation and described in Eck U.S. Pat. No. 4,330,945 employs a laser generated beam of light impinging upon targets spaced from the laser and positioned on the vehicle remotely from the laser projector. Because the vehicle is a three dimensional object, the laser and the targets may not be and indeed are likely not positioned in the same plane relative to the underside of the vehicle and the laser must sweep a plane, such as a vertical plane, to locate various objects therein. Because the typical laser heretofore projects only a narrow, pencil like beam of light, various rotatable mountings have been made for the laser projector. These mountings are often critical, for deviation in the spindles or bearings causes wandering or deviation of the beam of light as it sweeps upwardly and downwardly. Some such rotative structures are, by necessity, relatively precise and finely crafted and are therefore expensive in construction.
The present invention involves a mechanism which is relatively inexpensively constructed, can be mounted on the front end of the laser projector housing which selectively changes the emitted beam of light to a plane of light. Thus, the significantly more costly swivel or rotative mechanisms mounting the laser projector to various stands and tool bars may, in some intended uses, be omitted and the operator can more easily, by placing various targets in the plane of light, determine the position of the targets relative to the laser projector and therefore determine the correctness of the positions of the various body parts relative to each other, i.e. alignment.
The present invention generally includes a switching means which is mounted to the housing generally at the front wall of the housing and includes a holder member with a manually operated movable part which shifts from one position to another. In the first position of the movable part, the laser beam is substantially unaffected and continues to project out of the laser as a pencil beam of coherent, collimated light. In the second position of the shiftable member, the pencil beam of light passes through a lens which changes the orientation of the pencil beam to a plane.
The present invention is particularly useful with the system disclosed and claimed in the Kansas Jack Eck U.S. Pat. No. 4,330,945 and Kansas Jack has been licensed to use the present invention.